Internal-combustion engine



1,620,124 Mar 3, e, P. NIELSEN INTERNAL COMBUSTION ENGINE Filed May 17, 1923 HHHHH Q]; INVENTOR ATTORNEY ill Patented Mar. 8, 1927.

ITE STATES GEORGE E. NIELSEN, 0F SEATTLE, WASHINGTON.

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application filed May 17,

This invention relates to internal combustion engines and more especially to engines of the Diesel or semi-Diesel type and its object, generally, is the perfecting of engines of this character to render the same more efficient, durable, and economical in the consufiption of fuel. o

ore specific objects and advantages of the invention will appear in the following description, v

' e invention consists inthe novel construction, adaptation and combination of represented in Fig. 1. Fig. 3 is a view of an indicator card illustrating the pressures acting against the piston at various positions oi the same.

in said drawing, the numeral 5 designates the cylinder of an internal combustion engine having a head 6 containing an explosion chamber l. The chamber 7 is connected with the cylinder bore by means of a duct 8 in the partition 9 and in a tubular extension 10 which her. T e duct 8 is disposed axially of the cylinder bore and is of a conoidal shape tapering from said bore to its extremity within the chamber 7.

11 represents a fuel injection device of any known or suitable type whereby duel supplied under pressure through a pipe 12 1s delivered into a charge of air Within said combustion chamber to produce an explosive mixture. 13 represents the engine piston having a connecting rod 14': as usual. Said piston is formed or provided with a projection 15, preferably cylindrical, which is adapted to enter the duct 8 and ot a d1- ameter substantially equal-to the diameter Eitl ot the smaller end of said duct. 0

The extremity of the piston pro ection 15 is formed to provide a seat for a disk valve 16 which serves as a closure for air ports 17 extending to said seat from inlets provided in the periphery of the projection at about the midlength oi the latter.

The valve .16, as shown, is provided with a stem 18 acting in guide apertures pro,- vided respectively in the piston pro ection thereof equal to or slightly rotrudes upwardly into said cham 1923. Serial no. ceases.

and in a perforated cap element 19 which is secured to said projection.

Located in the peripheral wall of the cylinder bore at a distance from the top end less than the length of the piston stroke is a plurality of air-intake ports 20 which are disposed in spaced relations circumterentially of the cylinder bore and communicating with a distrlbutlng passage 21 provided in the cylins der wall.

22 represents a pipe leading from a pump or compressor (not shown) whereby air at a pressure of approximately four pounds per inch above that of the atmosphere is sup plied to said passage for delivery into the cylinder bore. Disposed op' osite to the air intake ports20, the cylin or is provided with a pluralityof exhaust ports 23 which communicate through the medium of a passage 24 with the pipe 25 for the discharge of spent gases from the cylinder.

To facilitate an understanding of the operation of the present invention T illus-v traits in Fig. 3 indicator diagrams showing fluid pressures per square inch estimated tor the e ective piston area of the usual type of en ine and'tor the effective piston area, inclu ing the projection 15, of my improved construction. Said indicator diagrams being taken for a cylinder bore of 40 inches, a piston stroke of i8 inches, and the diameter of the smaller end of the duct 8 and the diameter of the piston projection ten inches or one-fourth the diameter of the piston.

The column K of numbers at the left hand side of the diagram, Fig. 3, denote avera e pressure in pounds per square inch throug out the entire area of piston upon-ordinates taken from a base line M. The abscissa of the indicating diagram represent the strokes, the positions ofpoints on the indicating lines are taken from the axes X-X and "il -Y, respectively, for the compression and explosion strokes of the piston.

The operation of the engine above described is as follows:

A. charge of air admitted through the intake ports 20 into the cylinder bone is during t e following upward stroke of the pieton 13 thereby compressed and forced through the partition duct 8 into the charm her 7 to adord therein a pressure, for in stance, euivalent to loll-pounds per s uare inch it istributed over the entire piston area. The progressive pressures thus pro ltlli lid of the piston would be equivalent to about,

450 pounds per square inch, see line B E on the indicator diagram. I By reason, however, of the relatively small portion of the piston, that is to say-a transverse area of the piston projection 15being primarily exposed to the force of the explo? sion, the resultant force acting against the piston in the early part of its power stroke produces a comparatively small increase (about 30 pounds) of pressure per s uare inch with respect to the entire area 0 the piston. v

Such ressure' increase is represented upon the indicator by line BO and'occurs, say, in the first third-of the power stroke and during the remaining two-thirds of the power stroke, the diminishing pressure actmg against the piston as a whole is approxiiiatily as represented by the indicator line It is to be noted that the conical shape of the duct 8 affords a gradually increasing annular passage about the iston projection 15 in the withdrawal of t e latter from the duct 8 so that as the pressure of the combustion products in the chamber 7 lessens the eifective area for the flow of gases into the cylinder bore increases.

By such devices the power pressure resulting from the explosion at first acts against the projection only and later is applied throughout the end area of the piston. When the force of the power medium! has been practically expended the exhaust ports 23 are uncovered by the piston for the escape of the spent gases from the cylinder.

In the cycle of operation comprising a compression stroke and a power stroke as described above, the valve 16 responds to the pressures acting thereagainst as follows:

During the upward, or compression, stroke the valve remains seated until the projec: tion 15 (see Fi 2) enters the duct 8 to partially throttle t e duct, whereupon the valve is elevated by the flow of air through the by-pass ports 17 from the cylinder bore.

The valve is 0 en with respect to said ports only while t e projection 15 is travelling upwardly within the duct 8.

The operationof the invention will, it is thought, be understood from the foregoing description. The advantages of the invention reside principally in the provision of means which control the force produced by the explosion of fuel with respect to the piston, its connecting rod and the torsional. stresses of the associatedcrank shaft, and cause such forces and stressesto be transmitted more uniformly than with other constructions known to me.

The invention also eliminates the efi'ec'ts of the .excessive shocks or im ulses due to explosions as represented in Fig. 3 by indicator lines B-E and EA which is a fair illustration of other systems for com arison with the indicator lines B-C and A as attained by the present invention.

, What I claim, is,-

1. An internal combustion engine cylinder having a combustion chamber and 1ston bore. formed therein in spaced relation, a-

spacing member interposed between the combustion chamber and the cylinder bore, said spacing member having a tapered duct therethrough and in communication with the combustionchamber and the piston bore and a piston having a projection thereon of a uniform diameter throughout its length and of approximately the same diameter as the smallest diameter of the duct.

2. The combination of an internal combustion engine cylinder having an explosion chamber and piston bore formed therein and spaced apart by a wall having a truncated cone shaped duct therethrough and in com:

munication with the combustion chamber and the cylinder bore with a piston having a projection thereon of a diameter of approximately the smallest diameter of the duct and adapted to have reciprocal moveinent therein.

3. The combination of an internal combustion engine cylinder having an explosion chamber-and piston bore formed therein and spaced apart by a wall having a longitudinally and uniformly tapered duct connecting the combustion chamber and the cylinder bore, with a piston having a projection thereon of a diameter approximately equal to the smallest diameter of the duct and adapted to close and open the duct at the juncture of the duct and explosion chamber.

4. An internal combust-ionengine cylinder having a combustion chamber and a piston bore formed therein and spaced apart by a wall having a duct therethrough connecting the combustion chamber and the piston bore -and a piston having a projection thereon of explosive force to the piston head throughout the entire outward movement of the projection from the duct.

, 5. An internal combustion engine cylinder closing the duct when at its limit of movement toward the explosion-chamber, the duct being so tapered as to graduallyand uniformly deliver an increasing force of the explosion of a fuel charge in the combustion chamber to the head of'the piston during the outward movement of the projection from the duct. p

6. An internal combustion engine cylinder provided with a combustion chamber and a piston bore disposed in spaced relation, with a longitudinally tapered duct connectin them and a reciprocal piston within sai bore, said piston having a projection positloned to enter said duct and to close the same when the piston is in the extreme posi- 20 tion of itsmovement toward said combustion chamber and to gradually and uniformly open the duct when the piston moves away from said chamber whereby as the force of the gas explosion in the combustion chamber 25 diminishes, the field of said force is increasingly exerted against iston.

Signed at Seattle,- ashington, this 7th day of May,-1923.

GEORGE P. NIELSEN. 

